Janman has admitted to offering women lifts in Frankston around the time of the murders and has failed two lie detector tests.

On Saturday, the ageing man echoed a sentiment shared by the victims grieving families.

"I hope they find the true person that's responsible," he said.

Peter Sargent said he knows they all want the same thing.

"We want that vital bit of information be given to the police to help solve the case," he said.

Police are hoping the passage of time can help them solve these cases.

People who may have been unwilling or too frightened to come forward could now, years later, change their mind.

"We progress a lot of these investigations through relationships changing and if someone has assisted or knows something about this we are obviously appealing for them to come forward," Det. Ins. Hughes said.